JPH07108386A - Spot welding electrode - Google Patents

Abstract

PURPOSE:To prevent leakage of cooling water at the time of exchanging a tip and to improve fixation of the tip by providing a projecting part on the tip of a shank, fixing the cap-shaped tip attachably and detachably on the outside thereof and providing a small groove on the tip inside. CONSTITUTION:A copper member with a projecting part is welded 25 to the tip of the hollow bar-shaped shank 20 to form the projecting part 22. When a recessed part 32 of the cap-shaped tip 30 is fixed attachably and detachably on the projecting part 22, a gentle taper 21 is provided on the projecting part 22, a lubricant 23 is interposed and the recessed part 32 is press-fitted and stuck to the projecting part 22. The electrically conductive lubricant is desirable as the lubricant 23. In exchanging the cap-shaped tip 30, since a waterway in a hollow part 24 of the shank 20 is not communicated with the air, the water leakage is not caused and when the cap-shaped tip 30 is fixed on the recessed part 32, since fluid materials in the space between the tip 30 and the part 32 leak to the outside from the small groove 31, fixation of the tip is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to spot welding electrodes.

[0002]

2. Description of the Related Art An electrode for spot welding is composed of a shank 51 having a through hole 52 in the direction of the central axis for a cooling water channel and a tip 53 fitted and fixed to its tip, as shown in FIG.

Since the chip 53 is a consumable item, it must be frequently replaced with a new one. When exchanging the tip 53, the water channel was blocked, but water leakage could not be avoided.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrode rod for spot welding in which water leakage does not occur at the time of tip replacement.

[0005]

A means for solving the problems will be described with reference to FIGS. The electrode for spot welding according to the present invention is provided with the convex portion 22 at the tip of the shank 20, the concave portion 32 of the cap-shaped tip 30 is detachably fixed to the outer side of the convex portion 22, and the inner edge of the concave portion is close to the concave portion bottom surface. There is provided a small groove 31 reaching to.

[0006]

When the tip is replaced, the water channel is not opened, so that no water leakage occurs.

[0007]

EXAMPLE A hollow rod-shaped shank 20 is open at the base end side thereof, but a copper convex member is liquid-tightly fitted on the distal end side thereof and then welded 25 to form a convex portion 22. The copper cap-shaped tip 30 is fixed to the convex portion 22 to form the electrode rod 10. At least one small groove 31 extending from the upper edge of the inner surface of the recess to the vicinity of the bottom surface of the recess is provided.

When the shank 20 is attached to a holder (not shown), the water pipe 41 extending from the holder is attached to the shank 20.
It passes through the inside and reaches the vicinity of the inner surface in the convex portion 22. When the concave portion of the cap-shaped tip 30 is removably fixed to the convex portion 22, a loose taper 21 is provided on the convex portion 22 so that the cap-shaped tip 30 may be press-fitted and closely attached. The inner screw of the cap-shaped tip 30 may be screwed onto the outer screw of 22.

If the recessed portion of the cap-shaped tip 30 is detachably fixed by interposing the lubricant 23 on the outer side of the convex portion 22, the detachment is facilitated.

The lubricant 23 is preferably an electrically conductive lubricant such as a mixture of carbon and grease, but even with grease alone, the thin grease layer is partially cut off in the press-fitted state, and the convex portion 22 is formed.
The cap-shaped chip 30 and the cap-shaped chip 30 are in close contact with each other, and the electrical conductivity is maintained.

A fixing means other than welding may be used when the member with a copper convex portion is fitted in the hollow rod-shaped shank 20 in a liquid-tight manner and then fixed.

[0012]

When the cap-shaped tip 30 is replaced, the water passage in the hollow portion 24 of the shank 20 does not communicate with the outside air, so that water leakage does not occur. Also, the cap-shaped tip 30
Since the fluid in the space between the two is leaked to the outside from the small groove 31 when the is fixed to the recess 32, the fixability is improved.

Even when the present invention is applied to a shank with a non-water channel, it is useful for reducing the cost of the tip and facilitating the tip replacement.

[Brief description of drawings]

FIG. 1 is a vertical cut front view of a spot welding electrode according to the present invention.

FIG. 2 is an exploded view of FIG.

FIG. 3 is a sectional view taken along line AA of FIG.

FIG. 4 is a vertical cut front view of a spot welding electrode in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electrode rod 20 Shank 21 Tapered 22 Convex part 23 Lubricant 24 Hollow part 25 Welding 30 Cap-like tip 31 Small groove 32 Recess 33 Outer surface 41 Water pipe 42 Pore 51 Shank 52 Through hole 53 Tip

Claims (1)

[Claims] 1. A shank (20) is provided with a projection (22) at the tip thereof, and a recess (32) of a cap-shaped tip (30) is detachably fixed to the outside of the projection (22) and on the inner surface of the recess. An electrode for spot welding provided with a small groove (31) extending from the edge to near the bottom surface of the recess.